YOUTH is generally re garded as one of life’s more precious commodities, but few prize it as much as the classic dance community.

On Wednesday, Damian Woetzel – one of the most distinguished American dancers ever to grace our stages – retires from New York City Ballet at the ripe old age of 41.

Prudently, he has a master’s degree in public administration from Harvard, and a job – taking charge of the Vail International Dance Festival in Colorado. But it’s still early for a career switch, especially when you’re at the peak of your powers.

I thought of Woetzel’s retirement Tuesday night at “Fanfare,” part of City Ballet’s ongoing Jerome Robbins Festival.

The 1953 ballet, created to celebrate the coronation of Queen Elizabeth II and set to Benjamin Britten’s “Instruments of the Orchestra,” uses 34 dancers.

There’s nothing odd in that – nor was there anything especially odd in the perfectly adequate, even stylish, performance. Except that the dancers were not from New York City Ballet but The School of American Ballet.

One of the most promising is Megan Johnson, who’d earlier led “Concerto Barocco” at the SAB’s recent workshop performances and is just 18 years old. If she’s very, very lucky – and extraordinarily good – she might have 23 years ahead onstage. She must have been training for at least 10 already. As Woetzel could tell her, it’s a life of pure dedication.

The novelty of the evening was the revival after 24 years of Robbins’ 1974 “Four Bagatelles,” a vaguely Bournonville-style duet set to Beethoven that was all but casually danced by Ashley Bouder and Gonzalo Garcia.

Passing back to our theme of youth: Wednesday afternoon at the Metropolitan Opera House, American Ballet Theater showed off its newest male principal: 27-year-old Argentine virtuoso Herman Cornejo, dancing the barber-hero Basil for the first time in the razzmatazz “Don Quixote.”

Cornejo is one of those God-gifted dancers who endows his every step with a personal imprint. The breadth of his jumps, the speed of his turns and the totally unforced force of his personality make him a unique performer.

He partnered a nimble and perky Xiomara Reyes as Kitri. Also outstanding were Craig Salstein as the idiotically pompous Gamache and Misty Copeland with Joseph Philips (new to ABT this season and clearly a powerhouse acquisition) as the Gypsy Couple encamped in the second act.

NEW YORK CITY BALLET

New York State Theater, Lincoln Center; (212) 870-5570. Through June 29.